cap question

[ivtec]

Hi guys:i had here a satllite receiver that failed so i troubleshooted iti found a eletrolitic cap out of specs in the power so idid not same size same specs to fit there 4700uf,10v 105degrees,so on my scrap i found a biger cap olmost double size it did not fit there,and same 4700uf but 25v 85 degrees, then i soldered extra legs from some jumpers to the existing legs and soldered it in place,end of history it works now great,my question will it fail on the long run? or it'll be ok and i don't have to order same caps anymore for now,
i hate to make an order on my credit card just for 2 or 3 dollares?

[ivtec]

Re: cap question

Hi guys:i had here a satllite receiver that failed so i troubleshooted iti found a eletrolitic cap out of specs in the power so idid not same size same specs to fit there 4700uf,10v 105degrees,so on my scrap i found a biger cap olmost double size it did not fit there,and same 4700uf but 25v 85 degrees, then i soldered extra legs from some jumpers to the existing legs and soldered it in place,end of history it works now great,my question will it fail on the long run? or it'll be ok and i don't have to order same caps anymore for now,
i hate to make an order on my credit card just for 2 or 3 dollares?

Just want to add it's Michicon electrolitic 4700 10v 85degree fer cap

[Pentium4]

Re: cap question

I doubt it will last long, it's rated at 85C and the old one 105C. If the original was 105C then chances are it's in a high stress job, probably output filtering. What was the brand and series of the original? This one should work at least until you can order a new one though

[Behemot]

Re: cap question

Pics or didn't happen.

Generaly it is not a problem to use different spec'ed caps but you have to be sure (more or less) what exactly are you using and what will be the conditions there in the place you are soldering them in.

[ivtec]

Re: cap question

Pics or didn't happen.

Generaly it is not a problem to use different spec'ed caps but you have to be sure (more or less) what exactly are you using and what will be the conditions there in the place you are soldering them in.

Thanks Behemot for the intrest this temporare fix till i figuer out the right part,the cap that was there is a G-Luxon 4700uf 10v SM 105c 810 P(M)

these are the pics

[Behemot]

Re: cap question

Both are general purpose even though the Nichicon has higher ripple current due to the dimensions. It may work fine but true is it is old series I think and it has 1/4 the rated life of the original capacitor so it may fail soon.

If I am not mistaken, other caps in there are also bulging (I think I see Sam Young KMG and some Crapxon) so you will need to open in once more anyway, it cannot stay this way. Since it has been tested ESR-wise and usually lower-capacity higher-quality cap is better than the other way around, I think you can replace them quite fine with low-ESR caps of appropriate size in highest capacity you find. For example Chemi-Con KY is great line, or the newest KYA with higher capacity for every can size.

There is also possibility that you may lower the rated voltage, quite often caps for higher-than-circuit-working voltage are used (they have lower ESR and so). In that way you can increase their rated capacity so you may end with more or less the same nominal capacity. Check what voltages the caps filter and shop according to that

[ben7]

Re: cap question

Thanks Behemot for the intrest this temporare fix till i figuer out the right part,the cap that was there is a G-Luxon 4700uf 10v SM 105c 810 P(M)

these are the pics

I think this will probably be a good replacement.

Can you give us a list of the other capacitors in the power supply?
The info we need is the diameter (in mm), the height (in mm), the capacitance, the voltage rating, and the distance between the legs of the capacitor (again, in mm).

[Behemot]

Re: cap question

The KY is somewhat pricier but has 10000 hours endurance in this size.

[ivtec]

Re: cap question

Thanks guys i already have order the same specs, as for theother they are ok.
this one that i replaced has failed on all of this receivers by the hundreds.

thanks anyway